A young Adelaide woman facing up to 25 years in a Colombian prison after being arrested with 5.8kg of cocaine in her luggage says she was framed.

Cassandra Sainsbury, 22, was detained on April 11 at El Dorado International Airport in Bogota while attempting to board a flight back to Australia, her family said.

They say the woman was duped into bulk-buying boxed headphones containing concealed drugs from an acquaintance and attempting to carry them through customs.

Cassandra’s elder sister Khala has started an online campaign to raise funds for legal fees, saying her sibling is innocent.

“The authorities rushed through her hearing, and was denied bail. It sounds like they want to make an example of her,” Khala said on the page.

“Now because of being denied bail, she is now being held at Colombia’s biggest women’s prison, which is over-populated by about 50,000 people.”

But members of the public have taken to the fundraising page to express their doubts about her innocence.

Speaking on KIIS FM on Monday morning, Cassie’s mother Lisa Evans said her daughter wanted to buy gifts, including headphones, for family and friends to give away at her upcoming wedding to fiance Scott Broadbridge.

“She mentioned about these headphones that she wanted to get and this man said to her, ‘Well I know a guy that if you buy 16 or 18 of them he can give you a really good price’,” Ms Evans said. 

Ms Sainsbury’s family say the headphones were intended as gifts at her wedding to Scott Broadbridge (L).

“He had been helping her all week, taking her around and showing her places and just being a nice guy. Then when he said this Cassie said, ‘oh ok’.

“Then the day of her departure he came up to her hotel, gave her a package that was wrapped in black plastic we think, and she took it, put it in her luggage and this is where the naive bit comes in, she didn’t even rip it open to make sure there was just headphones in there.

“Whether he was just using her as bait and there was another big shipment trying to go through … so she would get caught, I just don’t know.”

Adelaide’s The Advertiser newspaper reported that 5.8 kilograms of cocaine was discovered divided across more than 15 pairs of headphones that Ms Sainsbury was given the morning of her flight home.

“She was with somebody she had met that could speak English and she was sightseeing, he was showing her around,” Khala Sainsbury was quoted as saying.

“They X-rayed her luggage and they found 5.8kg of cocaine concealed in packaging which was meant to be gifts for people for her bridal party and family friends,” she said.

“She’s supposed to be getting married next year and (the cocaine) was all concealed in the packaging of headphones she bought.”

Ms Evans earlier told Channel Nine’s Today show she didn’t know how someone could use her daughter to traffic drugs.

“Cassie is just, ‘I didn’t do it mum, you have got to get me out’ and crying hysterically,” Ms Evans said.

“She is just so scared that she is caught up on the other side of the world for something she didn’t do with no support over there, no nothing.

“The anger inside of me that someone could do this to an innocent girl for their own gain and to destroy several lives, not only Cassie’s but her family’s as well … I don’t know how a person could do that.”

Her family says she is facing up to 25 years in jail. She is currently in El Buen Pastor (The Good Shepherd) women’s prison.

Ms Sainsbury’s sister was due to pick her up from Adelaide Airport on Good Friday.

A spokesman for the Department of Foreign Affairs and Trade said it was providing assistance to an Australian woman arrested in Colombia but offered no further details due to privacy.

Khala said her sister arrived in Colombia on April 3 on a trip to promote personal training and had wanted to buy the headphones to give as gifts for her wedding party.

She said a male friend took her to a contact buy the headphones, which were pre-wrapped, The Australian quoted her as saying.

“She passed on the man’s number to police and the person was no longer contactable,” she said.

“There’s CCTV footage of where she met this guy.”

 – with AAP